Later, during the New Deal, Corcoran's influence grew and he was able to help many students of Frankfurter receive appointments in the Administration of President Franklin D. Roosevelt. Most were lawyers but many were also economists, and appointees were nicknamed "the happy hotdogs." [1] Some actually became Communists.

During FDR's presidency Corcoran worked in the White House as an intimate adviser and presidential speechwriter. At one point, Corcoran lived in the White House. Eventually Corcoran was outmaneuvered by Harry Hopkins for the position of Roosevelt's right-hand man. Corcoran, whose nickname was "Tommy the Cork", became a prominent Washington lawyer and fixer after leaving the White House.

Corcoran employed the Soviet Union agent Duncan Lee in his Washington law firm, Corcoran and Youngman,[2] after World War II. During the war Lee served as counsel to OSS head General William Donovan, and was the highest ranking KGB operative among nearly two dozen known Soviet agents who penetrated the OSS.[3]